Metallurgical Literature Research Articles

Hotspot Information Network and Domain Knowledge Graph Aggregation in Heterogeneous Network for Literature Recommendation

Tremendous academic articles face serious information overload problems while supporting literature searches. Finding a research article in a relevant domain that meets researchers’ requirements is challenging. Hence, different paper recommendation models have been proposed to address this issue. However, these models lack a more comprehensive analysis of the connections between the literature, the domain knowledge provided, and the hotspot information expressed in the literature. Previous models make it impossible to locate the appropriate documents for domain literature. Additionally, these models encounter problems such as cold start papers and data sparsity. To overcome these problems, this paper presents a recommendation model termed PRHN. Inputs of the model are the hotspot information network and the domain knowledge graph, which both were developed during the preceding research phase. After the query terms are extracted and the associated heterogeneous literature networks are formed, they are aggregated in a uniform hidden space. Similarity with the candidate set is determined to transform the search problem into a TOP N recommendation problem. Compared to state-of-the-art models, results generated by PRHN on public available datasets show improvement in HR and NDCG. Concretely, results on the metallurgical literature dataset are more conspicuous, with more remarkable improvement in HR and NGCC by approximately 4.5% and 4.2%.

Metastable alloys at moderate cooling rates

Abstract Using examples, old and recent, from the metallurgical literature, we examine the sources of metastable behavior in binary and ternary alloy systems that are subjected to cooling rates in the order of K/min to K/s. Because the metastability invariably involves enhanced unstable or suppressed stable crystalline phases, the key to this behavior must be sought in the crystallization kinetics.

Prototype Network for Text Entity Relationship Recognition in Metallurgical Field Based on Integrated Multi-class Loss Functions

It is of great significance to recognize the metallurgical entity relations in order to construct the Knowledge graph of Metallurgical Literature and to further understand the metallurgical literature. However, there are few researches on the textual entity relations in metallurgical fields either few marked Corpora. The syntactic structure of the same entity relationship category is relatively simple and has strong domain characteristics. The traditional entity relationship model can not identify the domain entity relationship well. Meanwhile the syntactic structure of the same entity relations class is relatively simple, and the syntactic structure is relatively simple in the recognition of entity relations in metallurgy field. Furthermore, the entities with similar syntactic structure often have the same entity relations and the different words in the sentence have different contribution to the entity relations. In order to solve the mentioned problems, this paper will combine the algorithm that can highlight the syntactic structure in sentences and improve the accuracy of the model with the Algorithm that can highlight the contribution of words in sentences and the loss function level integration is carried out in the framework of small sample prototype network, so as to maximize the advantages of each algorithm and improve the accuracy –firstly, in the coding layer of the prototype network, we use the CNN algorithm which can highlight the important words in the sentences and the TreeLSTM algorithm which can parse the sentences in the text so that the syntactic relations between the words in the sentences can be acted on in the relation recognition, the sentences are coded together by two algorithms, then, the EUCLIDEAN distance loss is calculated by using this high quality coding and the prototype coding, finally, the traditional entity relation recognition model with Attention Mechanism is integrated into the loss function, further highlighting the decisive role of important words in text sentences in relation recognition and improving the generalization of the model. The results showed that compared with the traditional methods such as CNN, RNN, PCNN and Bi-LSTM, the proposed method in this paper has better performance in the case of small sample data set.

The Shock and Spall Response of Kovar

The shock response and spall strength of Kovar®, an alloy of Fe-29Ni-17Co, are obtained using a single stage powder gun to achieve pressures between 6 and 55GPa by performing symmetric, planar impact tests. Above ~ 6.5GPa, the behavior shifts from a dispersive, continuous pressure rise to a shock, and it is shown that the material displays anomalous behavior at low pressures. Above 6.5GPa, the Hugoniot is described by a linear relationship between shock and particle velocity of US=2.06UP+3.54km/s. The spall strength, an engineering description of the spall phenomenon, was calculated and shown to increase from 3.6-7.4GPa as stress increases from 6-55GPa, and it is shown that the method of spall strength computation has a large effect. From previous studies on the iron-nickel system, the authors expected to observe evidence of an α → E phase transition in the material but did not. Upon examining the shock and metallurgical literature, high concentrations of Ni and Co will have competing effects on the phase transition, but the effect of Ni will likely dominate and decrease the phase transition pressure. Further experiments on the high alloy Fe-Ni-Co system are needed to understand Kovar's complex low pressure mechanical behavior.

Acid-base properties and structons: towards a structural model for predicting the thermodynamic properties of silicate melts

Phase equilibrium relationships in igneous systems can be estimated using empirical mathematical models based on multi-component regular solution formulae. Although these provide useable results within the fitted region, they can give very misleading values outside the compositional range of curve fitting. Moreover, they usually give poor estimates of the well-characterized melting relations of simple systems and do not relate to the large body of thermodynamic activity data available in the metallurgical literature, nor to spectroscopic, diffraction or computational models of silicate melt properties. The aim of this paper is to extend previous acid-base models of silicate melts and to use a quasi-chemical model to calculate the activities of quasi-chemical silicate mixing units, or structons, from combinations of the oxo-species used in quasi-chemical and polymer models to calculate oxide activities in metallurgy.

Software Tool for Modelling and Prediction of Low-Alloy Steels Properties and in Service Behaviour

After the publication in 1942 of a theoretical-empirical method to calculate hardenability of steels from its composition, a lot of methods to predict in service behaviour and properties of low-alloy steels have been divulged. This work describes how a low cost, user-friendly and wide-utility application can be developed from theoretical methods published in the specialised metallurgical literature. It will be also presented how these theoretical methods can be combined in order to simulate the in service behaviour of low-alloy steels and to approach reality as much as possible. The available results in the application are: Fe-C diagram, data for thermal treatments, TTT and TRC diagrams, tempering diagrams, Jominy curves and distribution of hardness in quenched and tempered bars.

Severe Plastic Deformation of a Commercial Aluminium-Lithium Alloy (AA8090) by Equal Channel Angular Pressing

The enhanced mechanical properties of crystalline materials are linked to very small grain sizes. The AA8090 is a commercial aluminium lithium alloy is referred in the metallurgical literature by its superplastic behavior linked as well to nano-grains as obtained by ECAP. On this research-work in progress, the 8090 aluminium alloy is studied after being processed in a 400 kN ECAE press up to nine passes through a 90º angle-die at 150 °C following Route A (constant path) at a processing speed of 10 mm/min. The room temperature mechanical properties of the extruded alloy are investigated through hardness measurements and tensile tests. Elastic measurements have been carried out by means of nanoindentation and ultrasonic testing, showing that both texture and nanostructuration of the processed alloy influence on the elastic constant of the processed material. In order to understand the mechanisms involved in the SPD-ECAP process, microstructural characterisation of the alloy has been carried out using different high resolution techniques such as Transmission Electron and Atomic Force Microscopy. TEM results have also been used in order to evaluate grain size evolution. From this analysis it is possible to see that after 4 passages the initial grains have already a high degree of dislocations. Among the characterisation techniques, AFM in the surface potential mode has been used to evaluate discontinuities in the matrix and /or decohesion between matrix and precipitates. After nine ECAP passages, no signs of decohesion at the interface have been observed neither using FEG-SEM nor using AFM.

A crystallographic identification of intermetallic phases in Al–Si alloys

Iron-rich intermetallic phases are well known to be strongly influential on mechanical properties in Al–Si alloys. Two important phases have been previously designated as the relatively benign α-phase (with a ‘Chinese Script’ morphology) and the detrimental β-phase (plate or needle-shaped). While the common morphologies and effects of these phases are generally agreed upon, there is some confusion in the literature regarding the chemistry and/or crystallography of these phases. Using a combination of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), electron backscatter diffraction pattern analysis (EBSD), transmission electron microscopy (TEM) and convergent beam electron diffraction (CBED), the present work showed that intermetallic phases in cast eutectic Al–Si alloy intermetallics are often misidentified in the current metallurgical literature. The α-phase particles were consistent with cubic Al19Fe4MnSi2 rather than hexagonal. The phase often identified a β-phase is actually consistent with the tetragonal Al3FeSi2 (more correctly designated as δ-phase) rather than monoclinic or orthorhombic.

Metastable alloys at moderate cooling rates

Abstract Using examples, old and recent, from the metallurgical literature, we examine the sources of metastable behavior in binary and ternary alloy systems that are subjected to cooling rates in ...

Binary Solutions and the Lever Rule Revisited

The partition coefficient for the normalized fraction of the low‐melting component X1 in a binary solution is simply related to the exchange coefficient KD, and for many systems of interest is a nearly linear function of the solid composition, providing a satisfactory estimate of the phase diagram from limited partitioning data. The analogous coefficient for the high‐melting component is nearly linear against the liquid composition. Both relations simplify the application of the Rayleigh distillation equation, either in an integrated form or numerically calculated with variable partition coefficient and continuously reset tangent composition, yielding accurate stepwise paths of fractional crystallization and fusion. The integrated form is useful if KD is constant and only one crystal phase is present. In the stepwise calculation, all variations in KD and modal ratios can be loaded onto the exponent of the Rayleigh equation and reset continually as the calculation proceeds. The residue produced on fractional crystallization or melting on a binary loop approximates rapidly to the pure endmember composition. Review of the geological and metallurgical literature shows that the amount of residue has been successfully calculated in many different ways, starting with N. L. Browen in 1913.

Artful Science: Enlightenment Entertainment and the Eclipse of Visual Education by Barbara M. Stafford

172 Book Reviews TECHNOLOGY AND CULTURE “futile for whom?”) Finally, Eamon’s suggestion of a trend from me­ dieval secrecy to early modern openness is overly simplistic, as is arguable from the evidence that he himself presents. Some of these criticisms reflect genuine methodological differences that cannot be adjudicated simplistically into a right or wrong ap­ proach. The great value of Eamon’s book lies in his detailed elabora­ tions concerning the books of secrets, as well as his insistence on their importance in the development of experimental philosophy. This cannot have been an easy task—the sources are scattered and cut across disciplinary boundaries such as the history of medicine and the history of alchemy. They have for the most part been deemed relatively trivial, if they have been considered at all. Although scholars may take issue with specific points of Eamon’s discussion, they will no longer be able to ignore the empirical interests of early modern popular culture as an issue for the history of experimental phi­ losophy. Pamela O. Long Dr. Long’s work in progress concerns issues of openness, secrecy, authorship, and intellectual property within premodern technical and military traditions. Her publica­ tions include a study of the ideal of openness in 16th-century mining and metallurgical literature. Artful Science: Enlightenment Entertainment and the Eclipse of Visual Edu­ cation. By Barbara M. Stafford. Cambridge, Mass.: MIT Press, 1994. Pp. xxx+ 350; illustrations, notes, index. $35.00. Barbara Stafford’s Artful Science: Enlightenment Entertainment and the Eclipse of Visual Education explores the sometimes shady world of pub­ lic “scientific” entertainments, experiments, and displays in the 18th century. The material she discusses is fascinating. For example, Vaucanson ’s automaton duck, which illustrated a hydraulic model of the digestive system, actually appeared to digest and defecate; Desagulier ’s experimental displays, elucidating Newtonian physics, were complete with the “visual appeal of clattering valves and hissing boil­ ers” (p. 178); and “pickled monsters” vexed the forerunners of cura­ tors of museums of natural history with practical and categorical problems of how to display them. Like the pickled monsters, Stafford’s book will cause difficulties for those who want their categories clearly defined. The lavishly illus­ trated Artful Science is not completely a history of science and technol­ ogy, or of popular entertainments, or of art. This is one of the strengths of the book and of Stafford’s scholarship in general. She continues the same kind of adventuresome cross-disciplinary leaps here that she embarked on in her previous book, Body Criticism (Cam­ bridge, Mass., 1991). In both books, the binding cross-disciplinary link is an epistemological notion of visuality. TECHNOLOGY AND CULTURE Book Reviews 173 Visuality also serves as a link between past and present in Artful Science. Stafford asserts that a shift from an oral/visual to a textual/ literate culture occurred during the Enlightenment. Today, because of new optical technologies, interactive software, and the telecommu­ nications and film industries, our culture is undergoing a shift back to a more visual mode of learning and understanding the world. In order to better prepare for this revolution-in-progress, Stafford argues, we need to cultivate or reactivate this visual dimension of knowledge and learning. Artful Science achieves this by interrogating the earlier oral/visual culture of the 18th century and by charting the significant moments in the Enlightenment transformation to a textual culture. That Stafford shows us the way through the medium of scientific and pedagogic entertainments is particularly timely, since educators, entrepreneurs, and artists are all leaping on the new tech­ nological bandwagon. Artful Science both illuminates and illustrates the epistemology of visuality and representation. Stafford emphasizes the nature and im­ portance of the visual in higher mental functions in her examination of “mathematical recreations,” scientific entertainments, and modes of exhibition. In a visual/oral culture, as opposed to a textual/literate one, the boundaries between art and technology, game and experi­ ment, image and speech are fluid; associative leaps are as important as a linear progression. Learning is a playful, conversational activity— interactive, to use a more contemporary term. The copious illustra­ tions, 197 in a 311-page text, provide a running visual commentary. The reader, however...

Emulsions in Metallurgical and Chemical Processes

A review of the metallurgical and chemical literature involving foams and emulsions is presented. Experimental techniques for the measurement of drop sizes in such systems are reviewed, and the basic mechanisms of drop breakup and coalescence are discussed, along with an analysis of the pertinent mass-transfer processes. A detailed discussion on a number of industrial processes using foams and emulsions is also presented.

A general enthalpy method for modeling solidification processes

In the present work, a general implicit source-based enthalpy method is presented for the analysis of solidification systems. The proposed approach is both robust and efficient. The performance of the method is illustrated by application to a number of problems taken from recent metallurgical literature.

A Viscoplastic Model for Single Crystals

A viscoplastic constitutive model is described in which deformation behavior is postulated on representative slip systems and the behavior of the entire crystal is determined by summing the slip on the active slip systems. By building in the slip geometry known from the metallurgical literature, it is possible to predict the anisotropic deformation behavior and to model in a straightforward manner other phenomena which have been described by metallurgists in crystallographic terms. Elevated temperature tension-torsion tests were run and used to verify the model’s predictive abilities. Ratchetting behavior under thermomechanical loading conditions is specifically addressed.

The relaxation of a double-well energy

This paper studies coherent, energy-minimizing mixtures of two linearly elastic phases with identical elastic moduli. We derive a formula for the “relaxed” or “macroscopic” energy of the system, by identifying microstructures that minimize the total energy when the volume fractions and the average strain are fixed. If the stress-free strains of the two phases are incompatible then the relaxed energy is nonconvex, with “double-well structure”. An optimal microstructure always exists within the class of layered mixtures. The optimal microstructure is generally not unique, however; we show how to construct a large family of optimal, sequentially laminated microstructures in many circumstances. Our analysis provides a link between the work of Khachaturyan and Roitburd in the metallurgical literature and that of Ball, James, Pipkin, Lurie, and Cherkaev in the recent mathematical literature. We close by explaining why the corresponding problem for three or more phases is fundamentally more difficult.

Deformation-related recrystallization processes

Recrystallization is a common microstructural transformation that occurs during deformation, metamorphism and diagenesis of rocks. Studies on minerals and rock analogues have demonstrated that a wide range of recrystallization mechanisms can occur. The range of mechanisms is related to the various ways in which two basic processes, grain boundary migration and new grain boundary formation combine to transform the microstructure. Two recent papers (Drury et al., 1985; Urai et al., 1986) have proposed different schemes for the description of recrystallization mechanisms. The purpose of this paper is to provide a unified framework for the description of mechanisms. Recrystallization mechanisms are divided into three main types; rotation mechanisms which principally involve the formation of new grain boundaries; migration mechanisms which principally involve grain boundary migration; and general mechanisms which involve both basic processes. A further distinction is made on the basis of the continuity of the microstructural transformation with respect to time. Each of the three main types of mechanism can be divided into a number of sub-types depending on whether the processes of grain boundary migration, new grain boundary formation and new grain formation occur in a discontinuous or continuous manner with respect to time. As the terms continuous and discontinuous have been used in the metallurgical literature to signify the spatial continuity of the microstructural transformation, the terms discontinuai and continual are used to refer to the temporal continuity of the transformation. It is recommended that the following aspects should be specified, if possible, in a general description of recrystallization mechanisms: 1. (1) How do the basic processes combine to transform the microstructure. 2. (2) If new grain development occurs, what is the development mechanism, and does new grain formation occur in a continual or discontinuai manner. 3. (3) If grain boundary migration is involved in the transformation, what is the migration mechanism (i.e. fast solute escape migration, slow solute loaded migration, fluid assisted migration, etc.), and is migration a continual or discontinuai process. The application of the unified scheme is illustrated by reviewing studies that have provided detailed information on the recrystallization mechanisms involved. The complicating effects of solid solution impurities, dispersed second phase particles and grain boundary fluid films are also considered and it is demonstrated that variations in content of these types of impurity can significantly effect the types of recrystallization that occur in a given material.

Mechanical properties of stainless steel orthodontic archwires

Sixty orthodontic archwire product/size combinations were studied from six manufacturers in simple bending and uniaxial tension. Data were obtained for wire diameters, elastic moduli, yield strength, tensile strength, and elongation at break. In addition the flexibility, the resilience, and the ratio of yield strength/ultimate tensile strength were determined. Results show that, in general, these parameters equal or exceed other values reported in the metallurgical literature and that the wire diameter has some influence on the parameters, presumably as a result of the cold work-strain hardening process. Among the various products investigated some were different and, for orthodontic purposes, were superior to alternative products. Within a given product the scatter of different wire sizes was often substantial and precluded more detailed interpretations of subgroups from being made.

The calculation of force on a weakly magnetic particle in a magnetic field

This paper considers the calculation of the force on a mineral particle in a magnetic field, a matter of relevance to wet and dry magnetic separators. The literature of physics rarely addresses this problem, magnetic theory concentrating more on waves. The metallurgical literature has many reviews of the performance of magnetic separators but force calculations are few and generally are carried out and discussed in terms of electromagnetic units. With the adoption of SI units it is important to address the force calculation problem again and the conversion of such problems from one system to another necessitates an understanding of the grounds of each system, that is the problem is more complicated than simple conversion factors would allow. Numerical examples are displayed.

Mixing models for gas stirred metallurgical reactors

The mixing of liquids in ladles, (0.5 ≦L/D ≦ 2.0), agitated by a centrally rising bubble plume, has been analyzed both theoretically and experimentally. An exhaustive review of previous metallurgical literature on mixing in ladles and furnaces demonstrates that the majority of previous investigators in the field consider mixing to be brought about primarily by turbulent diffusion phenomena. The present study clearly shows that mixing is a combination of both convection and eddy diffusion processes, neither of which can be disregarded for gas stirred systems. For predicting mixing times during such gas injection procedures, a simple empirical equation is proposed for axisymmetric systems:τ mαem −1/3L−1R5/3. Hereτ m is the 95 pct mixing time,e m is the specific energy input rate,R is the vessel radius, andL is the depth of liquid. On the basis of physical and mathematical modeling, the rate of liquid mixing in conventional gas injection ladle metallurgy operations is compared with those observed in C.A.S. (composition adjustment by sealed argon bubbling) systems. It was found that mixing in C.A.S. operations is relatively slow and highly insensitive to gas flowrates(i.e., specific energy input rates).

Comparisons of crystal hardening laws in multiple slip

Abstract This paper brings together and concisely reviews results from recent analytical investigations on single crystals (variously done alone or with students) in which predictions from different theoretical hardening laws are contrasted and compared with experimental studies. Finitely deforming f.c.c. crystals in both constrained and unconstrained multiple-slip configurations are considered. Four crystal hardening laws are given prominence. Two of these belong to a class of theories in which the physical hardening moduli relating rates-of-change of critical strengths (in the 24 crystallographically equivalent slip systems) to slip-rates are taken as symmetric. These are G.I. Taylor's classic isotropic hardening rule (proposed in 1923), which is almost universally adopted in the metallurgical literature for various approximate analyses of single and poly-crystal deformation, and a 2-parameter modification of Taylor's rule that has an empirical basis in the qualitative features of experimentally determined latent hardening in single slip. The other two hardening laws featured here belong to a class of theories that were introduced in 1977 by this author. This class requires the above moduli to be nonsymmetric and explicity dependent upon the current stress state in such a manner that the following consequences are assured. (1) The deformation-dependent hardening of latent slip systems necessarily develops anisotropically if there is relative rotation of gross material and underlying crystal lattice. (2) The theories admit self-adjoint boundary value problems for crystalline aggregates, hence a variational formulation. (The fact that symmetric physical hardening moduli do not permit variational formulations of polycrystalline problems was shown at the 1972 Warsaw Symposium.) The two members of this class considered here are the original (and simplest p possible) theory of rotation-dependent anisotropy, which was proposed by this author in 1977 and commonly has been referred to as the “simple theory,” and a modification of this theory introduced in 1982 by Peirce, Asaro and Needleman that lies between Taylor's rule and the simple theory in its predictions for finitely deforming f.c.c. crystals. (In a series of five papers during 1977–1979, the simple theory was shown to universally account for the experimental phenomenon of “overshooting” in single slip in both f.c.c. and b.c.c. crystals.) Theoretical results from the various hardening rules are contrasted and compared with finite strain experiments in the metallurgical literature. Both tensile-loaded crystals in 4, 6 and 8-fold symmetry orientations and compressively loaded crystals under conditions of channel die constraint are treated. A postulate of minimum plastic work introduced in 1981 plays a prominent role in the theoretical analyses, in many cases providing a unique solution to the slip system inequalities and deformation constraints (where applicable). The rather remarkable ability of the simple theory to reconcile diverse qualitative features of both constrained and unconstrained finited deformation of f.c.c. crystals is demonstrated. Finally, conditions for total loading (all systems active) in 6-fold symmetry are investigated, and certain concepts regarding the selection of active systems under prescribed straining are critically assessed.